Gas ejecting nozzle and projectile stabilizing fins for a self-propelled projectile



3,053,184 ILIZING Sept. 11, 1962 M. FRANols GAS EJECTING NOZZLE AND PROJECTILE STAB FINS FOR A SELF-PROPELLED PROJECTILE 2 Sheets-Sheet 1 Filed March l, 1960 SPt 11, 1962 M. FRANols 3,053,184

GAS EJECTING NOZZLEFABIID PROJECTI STBIL ING IZ FINS FOR A SEL ROPELLED JECTILE Filed March l, 1960 2 Sheets-Sheet 2 United States Patent Office amarsi Patented Sept. ll, 1962 poi-ate Filed Mar. 1, 1960, Ser. No. 12,129 Claims priority, application France Mar. 9, 1959 3 Claims. (Cl. 102-49) The present invention relates to self-propelled projectiles or rockets and more particularly to an improved gas ejecting and projectile stabilizing device for this type of projectile, said device being of an extremely light and sturdy construction and highly reliable in operation.

An object of the invention is to provide an improved nozzle arrangement and to this end there is contemplated a device in which a single axial nozzle for ejection of the propelling gases is longitudinally movable in a support adapted to be secured to the rear portion of lthe missile body. Around this nozzle, this support has mounted thereon a stabilizing iin arrangement, the ns of which are pivoted about transversely located pins, said nozzle and said fins having conjugated Contact surfaces such that a displacement of the nozzle in the support under the action of propelling gases from a forward inoperative position to a rear operative position, automatically causes said lin arrangement to be expanded.

Owing to this characteristic, springs which are in general rather fragile and difficult to be operated, and which are conventionally used in known devices to cause the fin arrangement to be expanded, can be completely omitted.

The invention also includes within its scope a self-propelled projectile provided with the aforesaid device.

Further features and advantages of the invention will be apparent from the ensuing description with reference to the accompanying drawings, to which the invention is in no way limited.

In the drawings:

FIG. 1 is a longitudinal cross-sectional view showing a device embodying the invention, in its rest position with the associated nozzle being partly shown as an outer view and partly in longitudinal section;

FIG. 2 is the corresponding rear View;

FIG. 3 is a longitudinal half-sectional view of the device in operative position, the fins being unfolded and the nozzle being shown as an outer view;

FIG. 4 is the corresponding end elevation seen from the rear;

FIG. 5 is a diametral axial-sectional view of the support forming a part of the device; and

FIG. 6 is a cross-sectional view taken through line 6 6 of FIG. 5.

In Ithe illustrated embodiment, the device which is adapted to be fixed at the rear of a body C of a selfpropelled projectile (rocket) comprises a metal support 1 having adjacent the forward end thereof an externally threaded portion 2 enabling it to be threaded into the rear internally threaded portion of body C. This support has axially formed therein a cylindrical aperture 3. From the rear sectional end thereof, it further comprises a plurality of radial slots 4, evenly distributed about the entire periphery thereof, as will be clearly seen in FIG. 6 of the drawings. This support has additionally formed therein a plurality of blind holes 5, one such hole corresponding to each slot 4 and crossing the latter at right angle. Finally at the forward end, the axial aperture 3 is provided with a stepped counter-bore 6-7 (FIG. l).

The aperture or bore 3 has sliding therein a forward portion having an outer cylindrical surface 8 of a nozzle member T. A seal 9 located in the portion 6 of the counter-bore provides a sealing engagement between the cylindrical portion 8 of nozzle T and the support l.

In the portion 7 of the counter-bore is located at 10 a ring formed of heat-insulating material and adapted to shield the bottom of the counter-bore from heat and to support the cake of propelling powder D.

The nozzle T has longitudinally extended therethrough the usual jet duct for the gases produced in the body C of the missile by the combustion of the self-propelling charge D. This duct or channel, from its upstream to its downstream end, converges from a to b, is cylindrical from b to c to form the neck portion of the nozzle, and finally diverges from c to d. The open rear end of the nozzle is preferably provided, as known per se, with an annular insert member l1 having small internal vanes 12 adapted to impart to the rocket a certain rotational motion about the longitudinal axis X-X thereof.

Around the nozzle T, each radial slit 4 of the support 1 has located therein a stabilizing iin A. Each vane A is pivotally mounted in the slit 4 by means of a pin 13 extending into the corresponding blind hole 5. Thus, each n is capable of oscillating about a transverse axis orthogonally disposed in relation to the longitudinal axis X-X of the device, between the folded position shown in FIGS. 1 and 2 and the unfolded position illustrated in FIGS. 3 and 4.

The fins can be held in the folded position shown in FIGS. l and 2 by known means, e.g. a removable belt B which is removed when the projectile is introduced into the launching tube or any other type of launching device.

Each iin A preferably comprises on the longitudinal edge thereof which is due to be directed forward when the fins are in their unfolded position (FIGS. 3 and 4), a double bevel 14.

The nozzle T and each of the fins A are designed so as to comprise conjugated locking surfaces.

To this end, the nozzle T is provided from front to rear and from cylindrical surface 8 which is slidable in the bore 3, a frustoconical shoulder 15 provided by the rearwardly-extending forward face of a cylindrically-bottomed groove 16 having a frustoconical forwardly-directed rear face 17; this groove is followed by a cylindrical portion 18, which is in turn followed by a transverse rearwardly extending shoulder 19 and iinally by a long frustoconical surface 20 which diverges rearwardly.

Each lin A includes a forward section 21 adapted to cooperate with the frustoconical shoulder 15, when said iin is in its unfolded position (FIGS. 3 and 4) and an inner edge comprising from rear to front: a first portion 22 which diverges rearwardly relative to the bevel 14, -a bead or projection 23 which extends forwardly and takes a transverse position when the fin is in its folded position (FIGS. 1 and 2), a long portion 24 which offers in respect of the bevelled outer edge 14 the same amount of bias as the portion 20 of the nozzle T has in relation to the axis X-X, and finally, a rear relief portion 25.

The relative longitudinal positions of the aforesaid surfaces and edges are such that:

in rest position, with its tins folded, the nozzle Tis held in a forward position shown in FIGS. l and 2 by means of a double abutting action, viz: from front to rear by the rear shoulder 19 bearing against the bead 23, and from rear to front, by the frustoconical surface Ztl bearing against the biased edge 24;

In unfolded position of the fins (FIGS. 3 and 4), on the one hand, the nozzle T abuts from front to rear by its frusto-conical shoulder against the forward edge 21 of each iin, thus arresting the rearward motion of the nozzle and, on the other hand, each iin is arrested in its unfolded position by the engagement thereof with thenozzle both by the interaction of the conjugated surfaces 15, 21 and by the abutment of the bead 23 on the cylindrical surface of the nozzle.

The operation of the device is as follows: prior to the projectile being launched, the device is in the position shown in FIGS. l and 2; tins A are immobilized by the belt B and the nozzle T is accordingly maintained in its forward inoperative position by the conjugated surfaces Tdi- 23.

When the projectile is being loaded into a tube or any other launching device, the fins A are freed of the belt B but are temporarily held in their folded position by the tube or the guiding means of the launching device.

As soon as the projectile has been ejected from the tube or the guide, the self-propelling charge D enclosed in the body A having been previously ignited by any known means, the propelling or thrust gases exert on the frustoconical internal front face a-b of the nozzle T a pressure which, since it is directed from front to rear, tends to bring said nozzle from its front inoperative position (FIGS. l and 2) to the rear operative position (FIGS. 3 and 4), This motion is no longer prevented by the action of fins A, since 'they are no longer locked at the rear.

Under the action of the thmst exerted by the transverse shoulder 19 of the nozzle against the beads 23 of the tins, the latter are gradually rotated about their transverse pins 13 and pass from the folded position shown in FIGS. l and 2 to the unfolded position of FIGS. 3 and 4.

The rotational motion of the fins and the axial movement of the nozzle T are automatically stopped as soon as the position of FIGS. 3 and 4 is reached by the inter* locking of said nozzle T and fins A, due to the contacts 15-21 and 18-23.

Nozzle T and fins A are thus truly immobilized in their operative positions which have been reached, as described, under the sole action of the propelling charge, without any interference from any auxiliary means, and in particular, without the use of any conventional springs which form a part of all known devices purported to provoke the oscillatin g of the ns.

Thus, the device is of truly simple cbnstruction and is operated without the remotest possibility of failure, since the device is comprised by a very limited number of sturdy, fail-proof parts, which make it practically safe from any risk of fouling during the handling thereof.

It will be understood that this invention is in no way limited or confined to the described and illustrated embodiment thereof which has been merely chosen by way of an example. Thus, for example, the slots 4 instead of being axial and radially directed may remain radial but be slightly offset in relation to the axis X--X, so that the un- '4 folded fins would have a slight positive incidence towards the front of the device, enabling the projectile to have a rotational motion imparted thereto, said rotation supplementing the action of the small vanes l2 provided at the rear of the nozzle T or being substituted therefor,

Having now described my invention what I claim as new and desire to secure by Letters Patent is:

l. A self propelled projectile comprising a body having leading and trailing ends and defining an internal combustion chamber, a support on and extending rearwardly from said trailing end of said body, said support defining a bore extending rearwardly from said chamber, a nozzle displaceable rearwardly in said bore in response to gas escaping from said combustion chamber, said support deiining a plurality of radial slots adjacent and opening into said bore, tins in said slots, pivots connecting said ns to said support for pivotal movement between rst and second positions in which said fins are respectively and generally aligned along and obliquely relative to said bore, each fin having leading and trailing projections respectively spaced at greater and lesser distances from the axis of said bore and facing generally forward, each trailing projection, with the associated iin in said first position, extending into said bore, said nozzle including leading and trailing shoulders facing rearwar ly, said trailing shoulder being normally engaged against the trailing projections to prevent rearward movement of the nozzle, said ns in moving to said second position releasing said trailing shoulder and projecting the leading projections into said bore to engage said leading shoulder to limit rearward movement of said nozzle, said nozzle including a cylin drical section forwardly of said trailing shoulder and said trailing projections abutting said cylindrical section with the leading projections engaging said leading shoulder, said nozzle including a conical diverging section rearwardly `of said trailing shoulder, said fins including corresponding edges resting against said conical diverging Section with the ns in said rst position.

2. A projectile as claimed in claim l wherein, with said tins in said second position, said nozzle extends substantially to the rear of said tins.

3. A projectile as claimed in claim 1 wherein said leading shoulder has the form of a truncated cone and said trailing shoulder is substantially perpendicular to said bore.

References Cited in the tile of this patent UNITED STATES PATENTS 

